ACOUSTO-OPTIC TUNABLE ULTRAVIOLET SNESOR

THE EFFECTIVENESS OF KINETIC ENERGY SPACE-BASED INTERCEPTOR MAY BE CONSIDERABLY ENHANCED BY ON-BOARD UV SENSORS CAPABLE OF DETECTING A POTENTIAL TARGET'S UV SIGNATURE. SUCH UV SENSORS MAY PLAY A CRITICAL ROLE IN TARGET IDENTIFICATION, TRACKING, SEEKING AND DISCRIMINATION AND MAY PROVE INSTRUMENTAL FOR EARLY WARNING OF ATTACK AND KILL DETERMINATION. SPACE-BASED APPLICATIONS, IN PARTICULAR, HAVE CREATED AN URGENT NEED FOR MINIATURE TUNABLE IMAGING UV SENSORS. IN THIS INVESTIGATION, ACOUSTO-OPTIC TECHNIQUES ARE BEING USED TO DEVELOP A SMALL SIZE, LOW MASS ACOUSTO-OPTIC TUNABLE UV FILTER (AOTF) WITH HIGH SPECTRAL RESOLUTION, RAPID WAVELENGTH SCANNING CAPABILITY ASWELL AS RANDOM ACCESS WAVELENGTH SELECTION, AND TWO-DIMENSIONAL SPECTRALLY-RESOLVED IMAGING CAPABILITY. THE AOTF ESSENTIALLY CONSISTS OF A PIEZOELECTRIC TRANSDUCER BONDED TO A BIREFRINGENT CRYSTAL. EXCITATION OF THE TRANSDUCER BY AN APPLIED RF MODULATES THE INDEX OF REFRATIONVIA THE ELASTO-OPTIC EFFECT. THIS GENERATES A MOVING PHASE GRADIENT WHICH UNDER PROPER CONDITIONS WOULD DIFFRACT PORTIONS OF AN INCIDENT LIGHT BEAM. BOTH COLLINEAR AND NON-COLLINEAR CONFIGURATIONS ARE BEING INVESTIGATED TO ACHIEVE NON-CRITICAL PHASE MATCHING. DESIGN PARAMETER TRADE-OFFS ARE BEING AIMED AT MINIMIZING THE SIZE OF THE DEVICE. CHARGE-COUPLED DEVICE (CCD) ARRAYS AND MICROCHANNEL ARRAY-MULTIANODE DETECTORS ARE BEING EVALUATED. FLAST GATE CCD ARRAYS WITH POTENTIAL FOR 100% QUANTUM EFFICIENCY IN THE UV ARE RECEIVING SPECIAL ATTENTION. SUCCESSFUL DEVELOPMENT OF THE AOTF UV SENSOR WOULD COMBINE THE SPATIAL IMAGING CAPABILITY OF AN INTERFERENCE FILTER AND THE TUNABILITY OF A GRATING SPECTROMETER WITH A SIZE/MASS REDUCTION OF AT LEAST TWO ORDERS OF MAGNITUDE OVER CURRENTLY AVAILABLE SYSTEMS. ANTICIPATED BENEFITS EXIST IN SPACE-BASED INTERCEPTORS, WHERE SMALL SIZE AND MASS ARE OF CRITICAL IMPORTANCE. ADDITIONAL APPLICATIONS INCLUDE GEOPHYSICAL STUDIES, LIDAR REMOTE DETECTION OF ATMOSPHERIC CONSTITUTENTS, AND ANALYTICAL FLUORESCENCE SPECTROSCOPY.